This black t-shirt features a humorous design for those who love math and celebrating birthdays. The bold text reads "I AM √1521 YEARS OLD," a playful way of saying "39 years old" for math enthusiasts. The shirt appears to be made of a soft, comfortable fabric, ideal for casual wear. It's a great conversation starter and a fun addition to any wardrobe. Wear it to birthday parties, math meetups, or just around town to showcase your unique sense of humor and love for numbers. It's a perfect gift for math teachers, students, or anyone who appreciates a clever mathematical joke.